scholarly journals Roles of MgO and Al2O3 on the Viscous and Structural Behavior of Blast Furnace Primary Slag, Part 1: C/S = 1.3 Containing TiO2

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 866 ◽  
Author(s):  
Tingle Li ◽  
Changyu Sun ◽  
Sunny Song ◽  
Qi Wang
Keyword(s):  
Blast Furnace ◽  
Network Structure ◽  
Equilibrium Phase ◽  
Phase Region ◽  
Structure Characterization ◽  
Al2o3 Content ◽  
Slag Viscosity ◽  
Stable Operation ◽  
The Difference ◽  
Cylinder Method

This research provides fundamental insight into the roles of MgO and Al2O3 on the viscous and structural behaviors of CaO−SiO2−MgO−Al2O3−10 mass% TiO2−5 mass% FeO (CaO/SiO2 = 1.3) system primary blast furnace slag. The slag viscosity is measured by the rotating cylinder method, which is essential to the efficient and stable operation of a blast furnace. The network structure characterization of the quenched vitreous samples was conducted using Fourier Transformation Infrared (FTIR) and Raman spectroscopy. Unusual viscous behaviors (that the slag viscosity and the activation energy decrease or increase with increasing MgO or Al2O3 content) were observed, corresponding to changes in the network structure certified by FTIR and Raman analyses. It seems that the addition of MgO and Al2O3 prefers to modify the Si−O and Ti−O network in the present slag. When the slag composition reaches 10% MgO and 12% Al2O3, unexpected viscous behaviors (that MgO increases viscosity and Al2O3 decreases viscosity) are discovered. The roles of MgO and Al2O3 could be interpreted by changes in the arrangement structure of ions in liquid, corresponding to changes in the primary equilibrium phase region determined in phase diagrams and variation in the difference between the experimental and liquidus temperature, respectively.

scholarly journals Influences of Al2O3 and TiO2Content on Viscosity and Structure of CaO–8%MgO–Al2O3–SiO2–TiO2–5%FeO Blast Furnace Primary Slag

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 743 ◽  
Author(s):  
Tingle Li ◽  
Changyu Sun ◽  
Sunny Song ◽  
Qi Wang
Keyword(s):  
Blast Furnace ◽  
Rotating Cylinder ◽  
Al2o3 Content ◽  
Slag Viscosity ◽  
Tio2 Content ◽  
X Ray ◽  
Viscosity Variation ◽  
Cylinder Method ◽  
Networks Structure ◽  
Ftir And Raman Spectroscopy

In view of the fact that Ti–bearing blast furnace primary slag has been explored limitedly and its viscosity–structural property is not fully understood, the phase compositions, viscosity and structure of CaO–8%MgO–Al2O3–SiO2–TiO2–5%FeO slag are investigated by X-ray diffractometer, rotating cylinder method, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy respectively, considering the effect of Al2O3 and TiO2. The critical temperature that is defined as the temperature below which the viscosity of slag increases quickly, could be explained by the relative amount of perovskite to melilite from phase compositions analysis. The slag viscosity first increases with increasing Al2O3 content from 10 to 15 mass%, and then decreases with the further increase of Al2O3 to 18 mass%. Increasing TiO2 content continuously lowers the viscosity. FTIR and Raman spectra results show that increasing Al2O3 or decreasing TiO2 content leads to complex Si–O and Ti–O networks structure, corresponding to the slag viscosity variation. The effect of weak linkages of Si–O–Al is more dominant when Al2O3exceeds 15 mass%, which results in the decrease of viscosity.

scholarly journals Influence of B2O3and Basicity on Viscosity and Structure of Medium Titanium Bearing Blast Furnace Slag

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lingtao Bian ◽  
Yanhong Gao
Keyword(s):  
Blast Furnace ◽  
Network Structure ◽  
Blast Furnace Slag ◽  
Slag System ◽  
Break Point ◽  
Slag Viscosity ◽  
X Ray Diffraction ◽  
Structure Variation ◽  
Point Temperature ◽  
Furnace Slag

The effects of B2O3and basicity (CaO/SiO2) on the viscous behavior and structure of medium titanium bearing blast furnace slag (MTBBFS) were investigated. High temperature viscosimeter was applied to measure the viscosities of CaO-SiO2-MgO-TiO2-Al2O3-B2O3slag system and X-ray diffraction (XRD), NBO/T ratio, and structure parameterQwere employed to analyze its network structure. The results showed that the viscosity decreased and break point temperature increased with increasing basicity to 1.20. However B2O3addition gave rise to a decrease in slag viscosity and break point temperature inspite of basicity. The more B2O3content leads to the more pronounced variation, especially for the slag with larger basicity. The conventional NBO/T formula was revised to predict the structure variation of relatively complicated medium Ti bearing slag based on the work of Yanhong Gao and other researchers. The increase of B2O3content in slag made parameterQturn fromQ2toQ1, suggesting that network structure became simpler. It was also noticed that the addition of B2O3could suppress the formation of perovskite.

scholarly journals Effect of Basicity and Al2O3 on Viscosity of Blast Furnace Slag and Thermodynamic Analysis

2021 ◽  
Author(s):  
Jian Zhang ◽  
Zhengjian Liu ◽  
Jianliang Zhang ◽  
Cui Wang ◽  
Hengbao Ma ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Blast Furnace ◽  
Constant Temperature ◽  
Slag Basicity ◽  
Al2o3 Content ◽  
Wave Number ◽  
Slag Viscosity ◽  
Slag Structure ◽  
Slag Temperature

With the increased use of laterite nickel ore, the impact of high Al2O3 slag on blast furnace smelting has gradually increased. In this paper, the effects of slag basicity and Al2O3 content on slag viscosity and enthalpy change under constant temperature conditions was investigated. The changes in slag structure were analyzed by activation energy and Fourier Transform Infrared (FT-IR) spectroscopy. The relationship between slag components and slag temperature and viscosity when slag heat is reduced was investigated. The results showed that the viscosity first slightly decreased and then significantly increased with increasing basicity at constant temperature. With the addition of Al2O3 content, the viscosity of the slag increases. The activation energy increases with increasing slag basicity and Al2O3. With increasing basicity, the [SiO4]4- tetrahedral unit trough depth becomes shallow, the [AlO4]5- asymmetric stretching band migrates to lower wave numbers, and the slag structure depolymerizes. With the increase of Al2O3 content, the trough of [SiO4]4- tetrahedra deepens and the center of the symmetric stretching band moves to a higher wave number. The [AlO4]5- asymmetric stretching band becomes obvious, indicating the complexity of the slag structure. When the heat decreases, the slag temperature increases as the basicity increases, and the slag thermal stability is better at the basicity of 0.95-1.05. As the Al2O3 content increases, the thermal stability of the slag becomes worse.

scholarly journals Influence of Al2O3 Content on the Melting and Fluidity of Blast Furnace Type Slag with Low TiO2 Content

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Hao Liu ◽  
Yuelin Qin ◽  
Yanhua Yang ◽  
Qianying Zhang ◽  
Nengyun Deng
Keyword(s):  
Blast Furnace ◽  
Viscous Flow ◽  
Slag System ◽  
Al2o3 Content ◽  
Slag Viscosity ◽  
Flow Activation Energy ◽  
Flow Units ◽  
Precipitated Phase ◽  
Flow Activation ◽  
Furnace Slag

The increasing usage of iron ores with high Al2O3 content significantly increases the amount of Al2O3 in blast furnace slag and consequently affects its performance. This work uses slag sampled on site to study the effects of changes in Al2O3 content on the fluidity of the CaO–SiO2–Al2O3–MgO–TiO2 slag system that is characterized by high Al2O3 and low TiO2 contents, as well as on the phase transition law during the cooling process. Slag viscosity exhibits a rising trend with an increase in Al2O3 content, and Al2O3 in the tested slag is alkaline. The viscous flow activation energy of molten slag rises from 157 kJ/mol to 172 kJ/mol with an increase in Al2O3 content, and the viscous flow units in the slag become large and complicated. When slag is cooled, the main precipitated phase is melilitite. Spinel, perovskite, and olivine are also observed. The crystallization amount of the melilitite phase decreases constantly with an increase in Al2O3 content.

Study on Viscosity of Titania Bearing Blast Furnace Slag

2011 ◽  
Vol 467-469 ◽  
pp. 1742-1745 ◽  
Author(s):  
Jin Zhu Zhang ◽  
Ling Wen ◽  
Ming Hua Long ◽  
Bi Neng Yang
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Orthogonal Design ◽  
Al2o3 Content ◽  
Slag Viscosity ◽  
Iron And Steel ◽  
Analytical Reagent ◽  
Bf Slag ◽  
Furnace Slag

The viscosity of blast furnace slag which was taken from Shuicheng Iron and Steel Group Co. Limited was experimentally measured by column whirling method using the ND-II slag viscosity tester. By adding analytical reagent CaO, SiO2, Al2O3, MgO and TiO2 in accordance with orthogonal design, the contents of compositions in slag were adjusted in CaO/SiO2=1.16-1.24, 14.06-17.06mass%Al2O3, 5-7mass%TiO2, 8.96-9.96mass%MgO. The results showed that the viscosity of BF slag decreased with increasing TiO2; when the Al2O3 content in the slag was 14.06%, the viscosity of BF slag had a lowest value, a highest value had for 15.56% Al2O3 content, and a lower value for 17.06% Al2O3 content. There is no significant effect on the viscosity by both the magnesia and the binary basicity.

Chemical Stress Relaxation of NR Networks Prepared in the Swollen State

1986 ◽  
Vol 59 (4) ◽  
pp. 541-550 ◽  
Author(s):  
Kyung-Do Suh ◽  
Hidetoshi Oikawa ◽  
Kenkichi Murakami
Keyword(s):  
Stress Relaxation ◽  
Network Structure ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Chemical Stress ◽  
Network Chain ◽  
Crosslinking Process ◽  
Dimensional Network ◽  
Chemical Relaxation ◽  
The Difference

Abstract From the experimental results of the present investigation, it is apparent that two kinds of networks which have a different three-dimensional network structure give quite different behavior of chemical stress relaxation, even if both networks have the same network chain density. The difference in three-dimensional network structure for the two kinds of rubber arises from the degree of entanglement, which changes with the concentration of the polymer chains prior to the crosslinking process. The direct cause of chemical relaxation is due to the scission of network chains by degradation, whereas the total relaxation is caused by the change of geometrical conformation of network chains. This then casts doubt on the basic concept of chemorheology which is represented by Equation 2.

scholarly journals Experimental Model Study of Liquid–Liquid and Liquid–Gas Interfaces during Blast Furnace Hearth Drainage

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 496 ◽  
Author(s):  
Weiqiang Liu ◽  
Lei Shao ◽  
Henrik Saxén
Keyword(s):  
Blast Furnace ◽  
Furnace Operation ◽  
Slag Viscosity ◽  
Two Dimensional ◽  
Furnace Hearth ◽  
Breakthrough Time ◽  
Initial Amount ◽  
Blast Pressure ◽  
Blast Furnace Hearth ◽  
Model Study

The smooth drainage of produced iron and slag is a prerequisite for stable and efficient blast furnace operation. For this it is essential to understand the drainage behavior and the evolution of the liquid levels in the hearth. A two-dimensional Hele–Shaw model was used to study the liquid–liquid and liquid–gas interfaces experimentally and to clarify the effect of the initial amount of iron and slag, slag viscosity, and blast pressure on the drainage behavior. In accordance with the findings of other investigators, the gas breakthrough time increased and residual ratios for both liquids decreased with an increase of the initial levels of iron and slag, a decrease in blast pressure, and an increase in slag viscosity. The conditions under which the slag–iron interface in the end state was at the taphole and not below it were finally studied and reported.

scholarly journals Reduction of titanium oxide in the presence of nickel by nonequilibrium hydrogen gas

2009 ◽  
Vol 24 (7) ◽  
pp. 2391-2399 ◽  
Author(s):  
Hidehiro Sekimoto ◽  
Tetsuya Uda ◽  
Yoshitaro Nose ◽  
Shigeo Sato ◽  
Hiroaki Kakiuchi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Relaxation Process ◽  
Reduction Potential ◽  
Hydrogen Plasma ◽  
Equilibrium Phase ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Energy Process ◽  
X Ray ◽  
The Difference

We investigated the reduction of TiO2 in the presence of Ni by nonequilibrium hydrogen gas, including low-temperature hydrogen plasma at 800 °C and supercooled monatomic hydrogen at 1000 °C. TiO2 was reduced to Ti2O3, which is not in equilibrium phase, by low-temperature hydrogen plasma. The results of x-ray diffraction and energy dispersive x-ray analysis in experiments at 1000 °C indicate that the thermodynamical reduction potential of supercooled monatomic hydrogen is almost the same as atmospheric hydrogen gas. However, the wide Ti3O5 layer formed only in the case of the reduction at 1000 °C by supercooled monatomic hydrogen. With these experimental facts, we speculate that the reduction mechanism by nonequilibrium hydrogen consists of two steps; the releasing energy process and the relaxation process. We can explain the difference of reduction products by nonequilibrium hydrogen gas on the assumption of the rate of the relaxation process between 800 and 1000 °C.

scholarly journals Research on battery pack dynamic equalization technology with improved flying capacitor

2020 ◽  
Author(s):  
Huang Chen
Keyword(s):  
Network Structure ◽  
Experimental Test ◽  
Battery Pack ◽  
Matrix Structure ◽  
Complicated Structure ◽  
Equilibrium Time ◽  
Test Platform ◽  
Circuit Structure ◽  
Depth Study ◽  
The Difference

Abstract Aiming at the problem that the traditional flying capacitor equalization circuit has long equilibrium time and complicated structure, based on the in-depth study of the existing capacitor equalization method, this paper proposes a bidirectional DC-DC equalization circuit topology based on switch matrix. Structure, improve circuit switch network structure, reduce the number of switches and capacitors in the circuit, simplify the equalization structure, combined with the advantages of bidirectional DC-DC converters can be used in both directions, according to the difference between the average voltage of the battery pack and the voltage of each cell. Any two cells in the battery pack areused for equalization purposes. By establishing an experimental test platform verification, the results show that the topology can reduce the equalization time under the premise of simplifying the circuit structure when equalizing any two cells.

A Methodology for Blast Furnace Hearth Inner Profile Analysis

2007 ◽  
Vol 129 (12) ◽  
pp. 1729-1731 ◽  
Author(s):  
Yu Zhang ◽  
Rohit Deshpande ◽  
D. Huang ◽  
Pinakin Chaubal ◽  
Chenn Q. Zhou
Keyword(s):  
Heat Transfer ◽  
Blast Furnace ◽  
Profile Analysis ◽  
Furnace Hearth ◽  
Temperature Distributions ◽  
Blast Furnace Hearth ◽  
Computational Fluid Dynamics Cfd ◽  
The Difference ◽  
New Algorithms ◽  
Face Temperature

The wear of a blast furnace hearth and the hearth inner profile are highly dependent on the liquid iron flow pattern, refractory temperatures, and temperature distributions at the hot face. In this paper, the detailed methodology is presented along with the examples of hearth inner profile predictions. A new methodology along with new algorithms is proposed to calculate the hearth erosion and its inner profile. The methodology is to estimate the hearth primary inner profile based on 1D heat transfer and to compute the hot-face temperature using the 3D CFD hearth model according to the 1D preestimated and reestimated profiles. After the hot-face temperatures are converged, the hot-face positions are refined by a new algorithm, which is based on the difference between the calculated and measured results, for the 3D computational fluid dynamics (CFD) hearth model further computations, until the calculated temperatures well agree with those measured by the thermocouples.

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